- Introduced `InjectXSearch` in `XAIConfig` to enable automatic injection of the native `x_search` tool when not explicitly declared. - Updated `XAIExecutor` to honor the `InjectXSearch` configuration, ensuring consistent tool availability. - Enhanced configuration handling with support for dynamic diffing to track changes in `InjectXSearch`. - Added comprehensive tests to validate `InjectXSearch` behavior, including preparation and tool choice synchronization. - Updated example config and documentation to outline `InjectXSearch` usage. Closes: #4339